On Tue, 2007-03-06 at 22:39 +0100, Franck Bui-Huu wrote: > - set PAGE_OFFSET to 0x90000000. > > You said that you already tried the second solution but it fails. I > don't see why though... Ok that makes sense for me now. Though on the opposite of other arch, on 32bits mips you will always have PAGE_OFFSET == PHYS_OFFSET + 0x80000000 because of fixed KSEG. Making it possible to change both confused me. I found the problem, I think these two liners are missing from your patch. My board now works correctly, with 2MB more free memory, thanks for this ! (and for the free tour in mm/ ;) Commit 6f284a2ce7b8bc49cb8455b1763357897a899abb introduced PHYS_OFFSET, but missed some virtual to physical address conversion. The following patch fixes it. Signed-off-by: Maxime Bizon <mbizon@xxxxxxxxxx> --- linux-2.6.20/include/asm-mips/pgtable.h 2007-02-04 21:22:45.000000000 +0100 +++ linux/include/asm-mips/pgtable.h 2007-03-07 17:28:20.000000000 +0100 @@ -75,7 +75,7 @@ * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ -#define pmd_phys(pmd) (pmd_val(pmd) - PAGE_OFFSET) +#define pmd_phys(pmd) (pmd_val(pmd) - PAGE_OFFSET + PHYS_OFFSET) #define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT)) #define pmd_page_vaddr(pmd) pmd_val(pmd) --- linux-2.6.20/include/asm-mips/pgtable-64.h 2007-02-04 21:22:45.000000000 +0100 +++ linux/include/asm-mips/pgtable-64.h 2007-03-07 17:28:47.000000000 +0100 @@ -199,7 +199,7 @@ { return pud_val(pud); } -#define pud_phys(pud) (pud_val(pud) - PAGE_OFFSET) +#define pud_phys(pud) (pud_val(pud) - PAGE_OFFSET + PHYS_OFFSET) #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) /* Find an entry in the second-level page table.. */ -- Maxime